The Obama administration has blocked health plans without hospital benefits that many large employers argued fulfilled their obligations under the Affordable Care Act.

Companies with millions of workers, mainly in lower-wage industries such as staffing, retailing, restaurants and hotels that hadn’t offered health coverage previously, had been flocking toward such insurance for 2015.

Plans lacking substantial coverage of hospital and physician services don’t qualify as “minimum value” coverage under the law and so do not shield employers from fines of $3,000 or more per worker, the Department of Health and Human Services said late Friday.